The present invention relates to systems for delivering gases. More particularly, the invention relates to a system employing a gas-specific outlet that is keyed to a same gas-specific adaptor.
Pressurized gas supply networks are known for providing a gas outlet station with a gas. A detachable adaptor mates with the outlet for establishing the gas flow under pressure from a gas supply outlet to secondary equipment for ultimate use of the gas.
For example, in medical treatment environments, such as hospitals, it is commonplace to have available wall or ceiling mounted gas outlet stations for supplying gases such as nitrogen, carbon dioxide, air, oxygen or nitrous oxide. The outlet station typically may be mounted together with a face plate assembly and a mounting box which is permanently installed in the wall or ceiling of the treatment area and to which a gas supply conduit is routed. The outlets stations are supplied by a permanently installed gas supply system connected to corresponding gas storage tanks or pumps which may be quite remote from any area of ultimate use of the gas. Such outlet stations may also include a vacuum or suction line service connection or other desirable gaseous fluid flow service connections.
For each different gas or service available at an outlet station, the outlet station commonly includes an adaptor connection assembly which is opened when connected with the proper adaptor to deliver gas via the adaptor to the connected secondary equipment or user, and is closed leak-tight when the adaptor is disconnected to preclude leakage of pressurized gas from the system into the ambient air of the hospital room.
Gas supply systems are known which provide schemes of non-redundant keying to ensure error free gas access. In such systems, the outlet and the adaptor are keyed together according to the gas type. Also, the outlet and the adaptor are clearly marked with their gas type, so the user can easily read the markings. Because of the keying, an oxygen outlet will only mate with an oxygen adaptor. The nitrogen, air, vacuum, or other gas adaptors will not fit into the oxygen outlet. Thus, oxygen cannot be supplied by mistake through an adaptor of the wrong gas type. In this same way each of the gas types have a corresponding uniquely configured outlet and mating adaptor.
Two known types of outlet to adaptor keying are the "Diameter Indexed Safety System" (DISS) and the "Quick Connection System" (QC). In DISS, the gas outlet valves for each of a plurality of different gases or services include unique diameters which differ from the diameters of outlet valves for all other gases. Accordingly, only the adaptors for the same gas type which have mating diameter plugs fit each such outlet valve.
In a QC system, each adaptor includes an elongated valve plug which is sized to engage with a matching outlet valve aperture. The engagement opens the valve and establishes a leak tight gas flow connection through the plug and adaptor to the secondary equipment and the user. The connection is secured or latched by a latch mechanism.
In one known type of QC system, the latch mechanism is separate from the valve plug. A latching pin is disposed in spaced parallel relationship with the elongated valve plug. When the adaptor is plugged in, the latching pin enters an aperture on the outlet and is engaged by a mechanism to hold the adaptor to the outlet. The latching pin has a cross-sectional shape, such as round or square, or other shape. The aperture provided in the outlet for accepting the latching pin has a matching shape. The spacing between the plug and latching pin in combination with the cross-sectional shape of the latching pin defines a keyed relationship such that each adaptor is engagable only with an outlet station of the same gas type. Such a system is described in U.S. Pat. No. 4,718,699, the disclosure of which is incorporated herein by reference.
In another type of QC system, the latch mechanism includes the valve plug and no separate latching pin is used. For keying, recesses are provided on the outlet at selected locations spaced around the aperture for receiving the valve plug. Corresponding pins are provided on the adaptor for mating with the recesses when the adaptor is plugged into the outlet. Each gas type has a unique pin and recess placement, so that only adaptors and outlets of matching gas types can be used together. Such a system is described in U.S. Pat. Nos. 4,844,409 and 3,563,267, the disclosure of which is incorporated herein by reference.
Just as proper adaptor-to-outlet station connections are of critical importance in medical gas supply systems, so too are proper matching of the various outlet station valves, face plates and latching assemblies to the permanently installed mounting box and the gas supply conduit associated therewith. The potential severity of the consequences of improper outlet station assembly is of such magnitude as to dictate a very high standard of care. Accordingly, non-redundant keying schemes are also known in the art for keying outlet valves or mounting boxes, and the like, in order to ensure error free assembly of the various outlet station components during system installation.
The prior art includes numerous examples of gas outlet station valve assemblies and cooperating adaptors, of which the following are exemplary: U.S. Pat. Nos. 2,905,487, 3,448,760, 3,563,267, 4,718,669, and 4,844,409.
Certain shortcomings of the prior art have been noted. Conventionally, different manufacturers of adaptors and medical gas outlets employ different keying structure for matching outlets for a specific gas to the corresponding adaptor for the same gas. Therefore, an adaptor made by one manufacturer does not fit into an outlet made by another manufacturer. Thus the existence of different adaptor connecting systems has resulted in distinct and mutually incompatible outlet station constructions thus limiting the choice of components in gas supply system design.
In view of the above-described deficiencies in the art there is a need for a device which accepts differently shaped adaptors for a given medical gas service.